Theorem

Part of speech: noun (n.)

1. That which is considered and established as a principle; hence, sometimes, a rule. Not theories, but theorems (Coleridge. By the theorems, Which your polite and terser gallants practice, I re-refine the court, and civilize Their barbarous natures. Massinger.

2. A statement of a principle to be demonstrated.

Part of speech: verb (v.)

To formulate into a theorem.